I recently had a service tech out to look at my low heat problem. Temp at closest register was 75. The tech checked the gas pressure and found it to be OK. He found the burner oriface partially plugged and cleaned it. He found a spider nest in the burner. After starting the furnace he commented that the flame was now strong. After he left we noticed that the air at the register felt cool. I checked the temp and it was 85. Is this normal? And if not I will call for another visit from the tech. PS, he did not check the register air temp during his visit. Is there anything else I can look at in the meantime?